The given question is incomplete. The complete question is as follows.
Carbon absorbs energy at a wavelength of 150 nm. The total amount of energy emitted by a carbon sample is [tex]1.93 \times 10^{5} J[/tex]. Calculate the number of carbon atoms present in the sample, assuming that each atom emits one photon.
Explanation:
It is given that the energy at which C-atom absorbs energy is 150 nm. So, energy emitted by the carbon atom will have same wavelength at which C-atom absorbs the energy.
As we know that relation between energy and wavelength is as follows.
E = [tex]\frac{hc}{\lambda}[/tex]
where, h = Planck's constant = [tex]6.624 \times 10^{-34} J sec[/tex]
c = speed of light = [tex]3 \times 10^{8} m/s[/tex]
[tex]\lambda[/tex] = 150 nm = [tex]150 \times 10^{-9}[/tex]
Therefore, energy of one carbon atom is calculated as follows.
E = [tex]\frac{hc}{\lambda}[/tex]
= [tex]\frac{6.624 \times 10^{-34} Js \times 3 \times 10^{8} m/s}{150 \times 10^{-9}}[/tex]
= [tex]1.324 \times 10^{-18} J[/tex]
As the total energy emitted by the carbon sample is [tex]1.93 \times 10^{5} J[/tex]. Let us assume that the number of C-atoms in the sample be x and it is calculated as follows.
[tex]E_{total} = n \times E_{1C-atom}[/tex]
n = [tex]\frac{E_{total}}{E_{1C-atom}}[/tex]
= [tex]\frac{1.93 \times 10^{5}}{1.324 \times 10^{-18} J}[/tex]
= [tex]1.45 \times 10^{23}[/tex]
Thus, we can conclude that number of carbon atoms present in the sample, are [tex]1.45 \times 10^{23}[/tex].
A rooster with white feathers is mated with a gray hen of the same phenotype. Among their offspring, 28 chicks are gray 31 are white. What is the simplest explanation for the inheritance of these colors in chickens?
Answer:
The chickens that were born from this cross show incomplete dominance.
Explanation:
The colors of chicken feathers are determined by two genes. A dominant "A" gene that determines black color and a recessive "a" gene that determines white color. In addition, chickens may present the gray color that occurs when the alleles establish an incomplete dominance, which is the type of inheritance that happens when a heterozygous individual (presents the Aa alleles) has an intermediate characteristic in relation to the characteristics determined by the two alleles .
Based on this, we can say that at the crossing shown above, there was an inheritance determined by incomplete dominance.
The inheritance of feather colors in chickens, given the mix of gray and white offspring, suggests a pattern of codominance, where the genes for white and gray feathers are neither dominant nor recessive and are expressed together in the offspring.
When a rooster with white feathers is mated with a gray hen and they produce both gray and white offspring, it appears that neither the white nor gray color is completely dominant over the other. Instead, each phenotype is expressed in the offspring, suggesting a codominant pattern where the alleles for feather color are neither dominant nor recessive and are expressed simultaneously in a unique phenotype, as is common in certain chicken breeds.Comparatively, in some other contexts, the colors may blend and display an intermediate phenotype, which is characteristic of incomplete dominance. For example, if black and white mice breed and result in all gray offspring, it would demonstrate incomplete dominance, where the black and white alleles blend to produce gray. An example in plants would be the snapdragon, where red and white parents result in pink offspring. However, in the case provided, since there are distinct gray and white offspring, codominance seems more likely.
Which are true of stroke volume? Choose all correct. (20) a. It is the volume ejected per beat. b. An average resting value for stroke volume is 5 L/min. c. Cardiac output is inversely related to stroke volume. d. Mathematically, stroke volume equals EDV-ESV.
Answer:
a. It is the volume ejected per beat
d. Mathematically, stroke volume equals EDV-ESV.
Explanation:
Stroke volume refers to the volume of blood which is expelled out by the left ventricle of the heart to the body.
The stroke volume can be measured with the echocardiogram which measures the EVD or End-diastolic volume which represents the volume before the contraction of the ventricle and the ESV or End-systolic volume which represents the residual volume after the contraction.
The Stroke volume is calculated by the difference between the EDV and ESV. The stroke volume for a normal person is measured is 70 mL per sec.
Thus, the selected option is correct.